Parse: use the EOF token method to lex inline method bodies

Mark the end of the method body with an EOF token, collect it once we
expect to be done with method body parsing.  No functionality change
intended.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@225765 91177308-0d34-0410-b5e6-96231b3b80d8